The present invention generally relates to an high-voltage connection enclosure and more particularly, to an improved enclosure for connecting high-voltage cables connected to high-voltage gas-filled tubes, for example, neon tubes used for signage.
High-voltage, gas-filled tubes have been widely used for signage for decades. Some neon signage has the gas-filled tubes depicting letters and numbers completely enclosed in a housing that protects the electrical components and electrical connections from the weather. With other sign constructions, the sign is composed of individual gas-filled tubes representing letters and numbers that are individually mounted to an exterior wall or other surface of a structure without the benefit of an enclosure over all of the components. In that construction, the individual gas-filled tubes must be wired together in a high-voltage circuit that is powered from a secondary winding of a transformer. In a known manner, the wire from a gas-filled neon tube has an electrode that is connected to a conductor or wire, for example, a high-voltage gaseous tube and oil ignition (xe2x80x9cGTOxe2x80x9d) cable. In many applications, the electrical connection between the neon tube electrode and one end of the high-voltage GTO cable is accomplished utilizing a known connector P-K connector. The other end of the GTO cable is then connected to either one side of the secondary winding of the transformer or an electrode of an adjacent gas-filled neon tube. Thus, the gas-filled neon tubes are connected in series with the secondary winding of the transformer. In some applications, a single GTO cable is connected to adjacent gas-filled tubes. While such a connection would seem to be efficient, since the PK connectors are often located within a wall of the structure, the diagnosis and correction of a fault is time consuming and difficult. In other applications, a GTO cable from one gas-filled tube is connected or spliced with a GTO cable from an adjacent gas-filled tube in a junction box. Such known junction boxes have at least one electrically conductive terminal to which the ends of both GTO cables are mechanically connected and secured, thereby electrically connecting the GTO cables together. Other terminal boxes have two electrically conductive terminals connected with a electrically conductive bar, and an end of each of the GTO cables is attached to one of the terminals.
Such junction boxes permit gas-filled neon tubes to be very easily connected together. In some applications, the P-K connectors extend through the exterior wall of a building; and the junction boxes are in a relatively protected environment. In other applications, the P-K connectors and the junction boxes are mounted on the exterior wall of the building, and thus, must be impervious to harsh weather conditions.
Of significant concern is the potential for arcing or a short circuit between the exposed ends of the GTO cable and any grounded metal component within the junction box. To minimize the potential for arcing within the junction box, regulations are implemented setting forth a minimum distance between a cable connection and a metal portion of the junction box. Over the years, the specified minimum distance has increased, and more recent regulations may require different minimum distances depending on whether the junction box is located inside or outside a structure. Operating in an environment in which the regulations constantly change is a particular challenge with respect to the junction box design.
Further, there is a continuing requirement to make junction boxes more reliable and easier to use. For example, some junction box designs have various loose parts that must be assembled in the process of splicing two cables together. Further, after the cable splice is made and the junction box is permanently mounted, all junction boxes are opaque; and therefore, the junction box must be opened or partially disassembled to check the integrity of the splice.
Therefore, there is a need for an improved enclosure for connecting the ends of high-voltage GTO cables that can be readily changed to meet regulations that are constantly changing. Further, there is a need for a junction box that permits the integrity of the splice to be checked without having to disassemble the junction box. Further, there is a need for a junction box design that is easier to handle in the connecting of the GTO cables.
The present invention provides a high-voltage connection enclosure that is less susceptible to arcing and short circuits that may potentially result in a fire. The enclosure of the present invention is easy to use and permits a visual inspection of the electrical connection between two GTO cables without having to remove a cover or in any way disassemble the enclosure. Further, the enclosure of the present invention automatically secures the GTO cables in the enclosure as an enclosure cover is attached. Thus, the present invention provides a more consistent, reliable and higher quality, high-voltage electrical connection between ends of GTO cables. The invention is especially useful in providing an electrical connection with a high-voltage, gas-filled tube used for signage in which the electrical connection is exposed to a wide range of temperature and moisture conditions.
In accordance with the principles of the present invention and the described embodiments, an apparatus is provided for enclosing an electrical connection between two high-voltage cables. The apparatus has an electrically nonconductive separator integral with a mounting base for receiving the high-voltage cables. An electrically nonconductive tubular cover extends over the electrical connection and the high-voltage cables and is releasably attached to the mounting base.
In one aspect of the invention, the separator has two passages in a base portion to separately receive the high-voltage cables. The high-voltage cables are extended beyond the mounting base, so that the electrical connection is separated from an electrically conductive portion of the mounting base by a desired spacing. The separator also has fingers that are moved by the tubular cover into contact with the high-voltage cables to secure the high-voltage cables in the separator.
In a still further aspect of the invention the electrically nonconductive cover is sufficiently transparent so that the electrical connection joining the high-voltage cables can be visually inspected through the cover.
In another embodiment, the present invention includes a method of electrically connecting two high-voltage cables by first inserting each of the high-voltage cables into a separate passage formed of a nonconductive material integral with a mounting base. Next the high-voltage cables are extended a distance beyond the mounting base equal to a desired separation between an electrical connection between the cables and an electrical conductor associated with the mounting base. The ends of the high-voltage cables are joined together to form the electrical connection; and then, an electrically nonconductive tubular cover is placed over the electrical connection and the high voltage cables and is releasably attached to the mounting base.
In an aspect of that invention, the method further comprises securing the high-voltage cables in the mounting base.
Various additional advantages, objects and features of the invention will become more readily apparent to those of ordinary skill in the art upon consideration of the following detailed description of the presently described embodiments taken in conjunction with the accompanying drawings.